Extension tool having a plurality of links

ABSTRACT

An extension tool includes a plurality of sequentially arranged links moveable to a first position, the plurality of sequentially arranged links rigidly fixed to one another in the first position, the plurality of sequentially arranged links defining a first passage and a second passage, the second passage being separate from the first passage when the plurality of sequentially arranged links are rigidly fixed to one another.

FIELD

The present subject matter relates generally to an extension tool havinga plurality of links and one or more passages therethrough.

BACKGROUND

Robotic arm assemblies are useful throughout various industries forperforming operations at, e.g., remote locations, hazardous locations,etc. At least certain robotic arm assemblies include a robotic armformed of a plurality of links joined together at respective joints.Additionally, a plurality of control wires may extend through therobotic arm, with each wire terminating at an individual link for movingsuch link relative to an aft-adjacent link. The control wires may becoupled to one or more motors within a base of the robotic arm assembly,such that the robotic arm assembly may control a movement of the roboticarm by increasing and/or decreasing tension on the plurality of controlwires.

In such a manner, robotic arms may be useful in reaching out-of-sightlocations within various environments. However, robotic arms maygenerally be cost prohibitive and/or more complicated than desired forcertain applications. Accordingly, a tool that may allow for a user toreach remote locations within an environment in a more cost efficientmanner would be useful.

BRIEF DESCRIPTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In one exemplary embodiment of the present disclosure, an extension toolis provided, the extension tool including a plurality of sequentiallyarranged links moveable to a first position, the plurality ofsequentially arranged links rigidly fixed to one another in the firstposition, the plurality of sequentially arranged links defining a firstpassage and a second passage, the second passage being separate from thefirst passage when the plurality of sequentially arranged links arerigidly fixed to one another.

In one exemplary aspect of the present disclosure, a method foroperating a selectively flexible extension tool including a plurality ofsequentially arranged links defining a first fluid flow passage and asecond fluid flow passage is provided. The method includes providing afirst fluid flow through the first fluid flow passage; and providing asecond fluid flow through the second fluid flow passage, the secondfluid flow passage being separate from the first fluid flow passage whenthe plurality of sequentially arranged links are joined together.

For example, in certain other exemplary aspects the opening is aborescope opening. These and other features, aspects and advantages ofthe present invention will become better understood with reference tothe following description and appended claims. The accompanyingdrawings, which are incorporated in and constitute a part of thisspecification, illustrate embodiments of the invention and, togetherwith the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appended Figs.,in which:

FIG. 1 is a schematic view of an extension tool in accordance with anexemplary embodiment of the present disclosure in a slacked position.

FIG. 2 is a schematic view of the exemplary extension tool of FIG. 1 ina tensioned position.

FIG. 3 is a schematic, cross sectional view of an extension tool inaccordance with another exemplary embodiment of the present disclosurein a slacked position.

FIG. 4 is a schematic, close-up view of the exemplary extension tool ofFIG. 3 in a tensioned position.

FIG. 5 is a first side view of a first link of the exemplary extensiontool of FIG. 3.

FIG. 6 is a second side view of the first link of the exemplaryextension tool of FIG. 3.

FIG. 7 is a close-up view of a junction between adjacent links of theextension tool depicted in FIG. 3.

FIG. 8 is a close-up view of one end of one of the links of FIG. 7.

FIG. 9 is a seal between adjacent links of an extension tool inaccordance with an exemplary embodiment of the present disclosure.

FIG. 10 is a seal between adjacent links of an extension tool inaccordance with another exemplary embodiment of the present disclosure.

FIG. 11 is a seal between adjacent links of an extension tool inaccordance with yet another exemplary embodiment of the presentdisclosure.

FIG. 12 a close-up, schematic view of a link of a plurality of links ofan extension tool in accordance with an exemplary embodiment of thepresent disclosure.

FIG. 13 a close-up, schematic view of a link of a plurality of links ofan extension tool in accordance with another exemplary embodiment of thepresent disclosure.

FIG. 14 is a schematic view of a gas turbine engine and extension toolin accordance with an exemplary embodiment of the present disclosure.

FIG. 15 is a flow diagram of a method for operating an extension tool inaccordance with an exemplary aspect of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to present embodiments of theinvention, one or more examples of which are illustrated in theaccompanying drawings. The detailed description uses numerical andletter designations to refer to features in the drawings. Like orsimilar designations in the drawings and description have been used torefer to like or similar parts of the invention.

As used herein, the terms “first”, “second”, and “third” may be usedinterchangeably to distinguish one component from another and are notintended to signify location or importance of the individual components.

The terms “forward” and “aft” refer to relative positions of a componentor system, and refer to the normal operational attitude of the componentor system. For example, with regard to an extension tool in accordancewith one or more the present embodiments, forward refers to a positioncloser to a distal end of the extension tool and aft refers to aposition closer to a root end of the extension tool.

The terms “coupled,” “fixed,” “attached to,” and the like refer to bothdirect coupling, fixing, or attaching, as well as indirect coupling,fixing, or attaching through one or more intermediate components orfeatures, unless otherwise specified herein.

The singular forms “a”, “an”, and “the” include plural references unlessthe context clearly dictates otherwise.

Approximating language, as used herein throughout the specification andclaims, is applied to modify any quantitative representation that couldpermissibly vary without resulting in a change in the basic function towhich it is related. Accordingly, a value modified by a term or terms,such as “about”, “approximately”, and “substantially”, are not to belimited to the precise value specified. In at least some instances, theapproximating language may correspond to the precision of an instrumentfor measuring the value, or the precision of the methods or machines forconstructing or manufacturing the components and/or systems. Forexample, the approximating language may refer to being within a 10percent margin.

Here and throughout the specification and claims, range limitations arecombined and interchanged, such ranges are identified and include allthe sub-ranges contained therein unless context or language indicatesotherwise. For example, all ranges disclosed herein are inclusive of theendpoints, and the endpoints are independently combinable with eachother.

Referring now to the drawings, wherein identical numerals indicate thesame elements throughout the Figs., FIG. 1 is a schematic view of anextension tool 100 in accordance with an exemplary embodiment of thepresent disclosure in a slacked position; and FIG. 2 is a schematic viewof the exemplary extension tool 100 of FIG. 1 in a tensioned position.Accordingly, it will be appreciated from the description herein that theextension tool 100 is a selectively flexible extension tool.

The extension tool 100 generally includes a base 102, a line assembly104, and a plurality of sequentially arranged links 106. The base 102generally includes a first plate 108, a second plate 110, and one ormore extension guides 112. For the embodiment depicted, the one or moreextension guides 112 includes a pair of extension guides 112 fixedlycoupled to the first plate 108 and extending in a lengthwise directionLW. The second plate 110 of the base 102 includes openings 114corresponding to the pair of extension guides 112, such that the secondplate 110 is slidable along the extension guides 112 in the lengthwisedirection LW away from the first plate 108 and towards the first plate108.

The line assembly 104 generally includes a root 116 coupled to thesecond plate 110 of the base 102 and a plurality of lines 118 extendingfrom the root 116. The plurality of lines 118 includes a first line 118Aand second line 118B. As will be appreciated from the discussion hereinbelow, the line assembly 104, and in particular the first and secondlines 118A, 118B, are operable with the plurality of sequentiallyarranged links 106 to move the plurality of sequentially arranged links106 between the slacked position (FIG. 1) and the tensioned position(FIG. 2). Further, it will be appreciated that for the embodimentdepicted, although the lines are depicted as being spaced from oneanother in a crosswise direction CW in the embodiment depicted forexplanatory purposes, they are actually aligned with one another in thecrosswise direction CW for the embodiment depicted.

As will be explained in greater detail below, the plurality ofsequentially arranged links 106 are spaced from one another when in theslacked position (FIG. 1) to allow the plurality of sequentiallyarranged links 106 to pivotably move relative to one another. Bycontrast, the plurality of sequentially arranged links 106 are pressedagainst one another when in the tensioned position (FIG. 2) to rigidlyfix the plurality of sequentially arranged links 106 to one another.

For the embodiment of FIGS. 1 and 2, it will be appreciated that each ofthe plurality of links 106 are designed to result in a specificrigidized shape when the plurality of links 106 are moved to thetensioned position. For example, a first link 106A of the plurality oflinks 106 defines a first geometry (i.e., length, curvature, etc.) and asecond link 106B of the plurality of links 106 defines a second geometry(i.e., link, curvature, etc.). The first geometry is different than thesecond geometry. In at least certain exemplary embodiments, in order toform the plurality of links 106 having specific geometries to facilitatea desired shape of the plurality of links 106, each of the plurality oflinks 106 may be formed through an additive manufacturing process(sometimes also referred to as 3D printing). Such may facilitate theformation of specifically shaped links 106 to be fitted within theplurality of links 106 of an extension tool 100 resulting in a desiredshape when moved to the tensioned position, yet still remaining flexibleenough to fit through an anticipated environment.

Further, with regard to the plurality of lines 118 of the line assembly104, it will be appreciated that each of these lines 118 may beconfigured as cables, ropes, threads, etc. Accordingly, it will beappreciated that the lines 118 are generally flexible (i.e., will notprevent the plurality of sequentially arranged links 106 from pivotablymoving relative to one another in the slacked position). Further, one ormore of the lines 118 may be formed of a metal material, such as asteel, tungsten, etc. Alternatively, however, the lines 118 may beformed of any other suitable material.

In at least certain exemplary embodiment, it will be appreciated thatthe extension tool 100 depicted in FIGS. 1 and 2 may include a toolimplement coupled to one of the plurality of links 106. For example, theextension tool 100 defines a distal end 122, and the tool implement maybe coupled to the link 106 at the distal end 122. In certain exemplaryembodiment, the tool implement may include one or more sensors, cameras,or both, and additionally, or alternatively, may include one or moredrills, laser tools, welding implements, rotatable implement (such as aPhillips head screwdriver bit, a flat head screwdriver bit, a Torx bit,Allen bit, Pozidrive, or the like), etc. In such a manner, the extensiontool 100 may facilitate performing mechanical operations on a part at aremote location, or along an obscure vector within an environment (e.g.,along a non-linear path within the environment) that would otherwise bemore difficult.

With one or more of the configurations, the extension tool 100 mayinclude a flexible driveshaft extending through an interior of theplurality of links 106, and more specifically, through a tube definedalong a length of the plurality of links 106 (later described as a firstpassage).

It will further be appreciated, however, that in other embodiments, theextension tool 100 may be configured in any other manner to performoperations at a remote location, or along an obscure vector, within anenvironment.

Specifically, for the embodiment shown, the extension tool 100 isconfigured such that the plurality of sequentially arranged links 106defines a passage therethrough when the plurality of sequentiallyarranged links 106 are in the tensioned position (FIG. 2).

More specifically, for the embodiment shown, the extension tool 100 isconfigured such that the plurality of sequentially arranged links 106defines a passage therethrough when the plurality of sequentiallyarranged links 106 are in the tensioned position (FIG. 2). For theembodiment depicted, the passage is a fluid flow passage. However, inother embodiments, the passage may not be configured to provide a fluidflow and instead may be configured to, e.g., act as a guide tube for atool.

It will be appreciated, that as used herein, the term “fluid flowpassage” refers to any substantially continuous passage through theplurality of sequentially arranged links 106 when the plurality ofsequentially arranged links 106 are in the tensioned position, capableof providing a gas or liquid flow to a location proximate the distal end122 of the plurality of sequentially arranged links 106, or extracting agas or liquid flow from a location proximate the distal end 122 of theplurality of sequentially arranged links 106.

More specifically, referring particular to FIG. 2, the plurality ofsequentially arranged links 106 together define a first passage and asecond passage, the second passage being separate from the first passagewhen the plurality of sequentially arranged links 106 are in thetensioned position. More specifically, still, for the embodiment shown,the first passage is a first fluid flow passage 124 and the secondpassage is a second fluid flow passage 126. However, as noted above, inother embodiments the first and/or second passage may not be configuredto provide a fluid flow and instead may be configured to, e.g., act as aguide tube for a tool.

The second fluid flow passage 126 is separate from the first fluid flowpassage 124 when the plurality of sequentially arranged links 106 are inthe tensioned position. In such a manner, separate fluids may flowthrough the respective first and second fluid flow passages 124, 126. Aswill be appreciated from the description herein, and particularly fromthe embodiments described below, in at least certain exemplaryembodiments, including the embodiment of FIG. 2, the first fluid flowpassage 124 is an inner fluid flow passage and the second fluid flowpassage 126 is an outer fluid flow passage. In such a manner, the innerfluid flow passage is positioned inward of the outer fluid flow passage,with the outer fluid flow passage substantially completely surroundingthe inner fluid flow passage. As such, the outer fluid flow passage maydefine a generally annular shape surrounding the inner fluid flowpassage.

However, in other exemplary embodiments, the first and second fluid flowpassages 124, 126 may be arranged in any other suitable manner. Forexample, in other embodiments, the first and second fluid flow passages124, 126 may instead run parallel and adjacent to one another, but maynot be arranged concentrically (e.g., one of the first or second fluidflow passages 124, 126 extending along one side of the plurality oflinks 106 and the other of the first or second fluid flow passages 124,126 extending along another side of the plurality of links 106).

Referring still to the exemplary embodiment of FIG. 2, the second fluidflow passage 126 is substantially fluidly isolated from the first fluidflow passage 124 when the plurality of sequentially arranged links 106are in the tensioned position. As used herein, the term “substantiallyfluidly isolated” refers to less than 10% of a fluid provided to arespective one of the first fluid flow passage 124 or second fluid flowpassage 126 transferring to the other of the first fluid flow passage124 or second fluid flow passage 126 during normal operations, includingthe operations described herein.

Referring still particularly to FIG. 2, it will be appreciated that theextension tool 100 further includes features for providing one or morefluid flows through the first fluid flow passage 124, the second fluidflow passage 126, or both. For example, for the embodiment of FIG. 2,the extension tool 100 further includes a first fluid flow device 128fluidly coupled to the first fluid flow passage 124, the second fluidflow passage 126, or both.

In particular, for the embodiment of FIG. 2 the first fluid flow device128 is fluidly coupled to the first fluid flow passage 124 through afirst conduit 130, and the extension tool 100 further includes a secondfluid flow device 132 fluidly coupled to the second fluid flow passage126 through a second conduit 134. In certain embodiments, such as theembodiment shown, the first fluid flow device 128 generally includes afirst pressurized fluid source for providing a first pressurized fluidflow 136 (shown schematically through conduit 130) through the firstfluid flow passage 124. The first pressurized fluid flow 136 may be,e.g., a heated gas flow, a pressurized gas flow, a heated liquid flow, apressurized liquid flow, etc.

Further for the embodiment of FIG. 2, the second fluid flow device 132similarly includes a second pressurized fluid source for providing asecond pressurized fluid flow 138 (shown schematically through conduit134) through the second fluid flow passage 126. The second pressurizedfluid 138 flow may include a different fluid flow than the first fluidflow 136 (e.g., a different gas, different liquid), may operate at adifferent temperature and/or pressure, etc.

For example, in certain exemplary embodiments the first pressurizedfluid flow 136 may be a heated gas flow operating at a first temperature(such as a first initial temperature as measured at a base end of theplurality of links 106) and the second pressurized fluid flow 138 maysimilarly be a heated gas flow operating at a second temperature (suchas a second initial temperature as measured at a base end of theplurality of links 106). The second temperature may be less than thefirst temperature to reduce a thermal gradient on a component on whichthe first and second pressurized fluid flows 136, 138 are directed.Additionally, or alternatively, the second temperature may be set to,e.g., ensure a thermal expansion of the first line 118A and the secondline 118B of the line assembly 104 matches a thermal expansion of theplurality of links 106 during operation, thereby reducing a tension onthe first and second lines 118A, 118B.

It will be appreciated, however, that in other exemplary embodiments,the extension tool 100 may operate in any other suitable manner. Forexample, as is depicted in phantom in FIG. 2, and other exemplaryembodiments, the second pressurized fluid source of the second fluidflow device 132 may instead be a fluid pump for urging a secondpressurized fluid flow 138′ from the second fluid flow passage 126 in adirection opposite the first fluid flow 136. With such a configuration,the extension tool 100 may, e.g., ensure any leakage of a firstpressurized fluid flow 136 through the first fluid flow passage 124(e.g., between adjacent links 106) is captured and not leaked into theenvironment, and/or, may operate to suction up excess of the firstpressurized fluid flow 136 at the distal end 122 of the plurality ofsequentially arranged links 106. For example, the first pressurizedfluid flow 136 may be a flow of oil or other lubrication being providedto a particular location within an environment, and the extension tool100 may operate the second fluid flow passage 126 as a vacuum to suctionup excess oil/lubrication at the particular location within theenvironment and further to capture any leakage from the first fluid flowpassage 124.

Additionally, or alternatively, the extension tool 100 may not includeseparate fluid flow devices for the first and second fluid flow passages124, 126. Instead, the first and second fluid flow passages 124, 126 maybe fed from the same fluid flow source (e.g., the first fluid flowsource 128). The fluid provided may be a heated fluid. The result maystill be a first fluid flow 136 at the distal end 122 at a firsttemperature greater than a second temperature of a second fluid flow138. Such may result from the second fluid flow effectively insulatingthe first fluid flow 136 and exchanging heat with the environment.

Referring again to both FIGS. 1 and 2, it will be appreciated that theline assembly 104 is operable with the plurality of sequentiallyarranged links 106 to move the plurality of sequentially arranged links106 between the slacked position (FIG. 1) and tensioned position (FIG.2). Specifically, the first line 118A and second line 118B of the lineassembly 104 may be fixed to the link 106 at the distal end 122 of theplurality of sequentially arranged links 106. When the first line 118Aand second line 118B of the line assembly 104 are tensioned (i.e., anamount of slack is taken out of the first and second lines 118A, 118B),a tension in the first line 118A and second line 118B presses each ofthe plurality of sequentially arranged links 106 against one another,fixing the plurality of sequentially arranged links 106 in position toform a substantially rigid extension. Notably, for the embodiment show,the plurality of links 106 includes a base link 140 fixed to the base102, allowing the first and second lines 118A, 118B to be pulled tight.

As will be appreciated more fully from the discussion below, it will beappreciated that the first line 118A defines a first displacement whenthe plurality of sequentially arranged links 106 are moved from theslacked position to the tensioned position (i.e., the amount of slacktaken out of the first line 118A), and similarly, the second line 118Bdefines a second displacement when the plurality of sequentiallyarranged links 106 are moved from the slacked position to the tensionedposition (i.e., the amount of slack taken out of the second line 118B).More particularly, the first and second displacement may be measured bysubtracting a first length 142 of the lines 118A, 118B between theplurality of links 106 and the root 116 (FIG. 1) when the links 106 arein the slacked position from a second length 144 of the lines 118A, 118Bbetween the plurality of links 106 and the root 116 (FIG. 2) when thelinks 106 are in the tensioned position.

For the embodiment shown, the first displacement is substantially equalto the second displacement. For example, in at least certain exemplaryembodiments, the first displacement may be within a 5% margin based on avalue of the first displacement, or more specifically may be within a 2%margin of the second displacement based on the value of the firstdisplacement.

As will also be appreciated more fully below, the substantially equaldisplacements of the first line 118A and the second line 118B areaccomplished at least in part due to a positioning of a plurality ofline guides (see, e.g., FIGS. 7 and 8) within the plurality ofsequentially arranged links 106. In particular, the line guidesfacilitate each pair of adjacent links 106 pivotably moving relative toone another about a pivot reference line with the first line 118A andsecond line 118B positioned along the pivot reference line at arespective end of the link 106. For example, for the embodiment of FIGS.1 and 2, the plurality of sequentially arranged links 106 form anon-linear shape when moved to the tensioned position, and morespecifically, define a two-dimensional, nonlinear shape in the planedepicted (i.e., in a plane defined by the lengthwise direction LW andthe crosswise direction CW). Each of the adjacent pair of sequentiallyarranged links 106 is configured to pivot about a respective pivotreference line perpendicular to the plane depicted in FIG. 1, and thefirst and second reference lines 118 at the respective ends of therespective links 106 along the respective pivot reference line. Such isdescribed in more detail below.

Briefly, it will be appreciated that the term “pivot reference line”generally refers to a reference line about which one link most easilypivots relative to another link during normal operation.

Referring now to FIGS. 3 and 4, an extension tool 100 in accordance withanother exemplary embodiment of the present disclosure is provided. FIG.3 depicts the exemplary extension tool 100 in a slacked position andFIG. 4 depicts the exemplary extension tool 100 in a tensioned position.The exemplary extension tool 100 may be configured in a similar manneras exemplary extension tool 100 described above with reference to FIGS.1 and 2. For example, the exemplary extension tool 100 of FIGS. 3 and 4generally includes a plurality of sequentially arranged links 106, aswell as a line assembly 104 having a first line 118A and a second line118B operable with the plurality of sequentially arranged links 106 tomove the plurality of sequentially arranged links 106 between theslacked position (FIG. 3) and the tensioned position (FIG. 4).

As with the embodiment of FIGS. 1 and 2, for the embodiment of FIGS. 3and 4, the first line 118A defines a first displacement when theplurality of sequentially arranged links 106 are moved from the slackedposition (FIG. 3) and the tensioned position (FIG. 4) and the secondline 118B defines a second displacement when the plurality ofsequentially arranged links 106 are moved from the slacked position(FIG. 3) and the tensioned position (FIG. 4). The first displacement issubstantially equal to the second displacement.

As noted above, such may be accomplished at least in part due to apositioning of the lines 118 at the ends of the respective links 106.For example, for the embodiment shown, the plurality of sequentiallyarranged links 106 generally includes a first link 106A and a secondlink 106B spaced from one another when in the slacked position to allowthe second link 106B to pivotably move relative to the first link 106Aabout a pivot reference line 148. The first line 118A and the secondline 118B of the line assembly 104 are positioned along the pivotreference line 148 at an end of the first link 106A proximate to thesecond link 106B.

More specifically, the first link 106A extends between a first end 150and a second end 152, and similarly, the second link 106B extendsbetween a first end 154 (located proximate the second end 152 of thefirst link 106A) and a second end 156. For the embodiment depicted, theplurality of sequentially arranged links 106 form a nonlinear shape whenmoved to the tensioned position, and more specifically, define athree-dimensional, nonlinear shape when moved to the tensioned position(FIG. 4).

As such, the first link 106A defines a first pivot reference line 148Aat the first end 150 of the first link 106A and a second pivot referenceline 148B at the second end 152 of the first link 106A (or moreparticularly, the first link 106A defines the second pivot referenceline 148B at the second end 152 of the first link 106A with the firstend 154 of the second link 106B). The first pivot reference line 148A isout of plane with the second pivot reference line 148B. Morespecifically, the exemplary extension tool 100 defines an X direction, aY direction, and a Z direction collectively forming an orthogonalcoordinate system. As depicted in FIG. 3, the first pivot reference line148A and second pivot reference line 148B are nonparallel in the X-Yplane, and as shown in callout circles A and B, are similarlynonparallel in the X-Z plane.

Further, referring still to FIG. 3, it will be appreciated that thesecond link 106B also defines pivot reference lines 148. Specifically,as briefly noted above, the second link 106B defines the second pivotreference line 148B at its first end 154 along with the second end 152of the first link 106A, and the second link 106B further defines a thirdpivot line 118 at its second end 156. The third pivot line 118 issimilarly out of plane with the first pivot line 118 and the secondpivot line 118 (see, also, callout Circle C).

Notably, the pivot lines 118 refer to an imaginary reference linegenerally about which one link 106 pivots relative to another link 106during normal operations when in the slacked position. The pivotreference lines 118 may be set by a shape of the adjacent links 106 andgravitational forces when held out in the slacked position, and may insome cases be influenced by the positioning of the first and secondlines 118A, 118B.

Further, with the embodiment depicted, the first line 118A and thesecond line 118B of the line assembly 104 are generally arranged alongpivot lines 118 at a respective end of a respective link 106. As will beshown more clearly in the Figures below, each of the plurality of links106 includes one or more line guides for holding the plurality of lines118 of the line assembly 104 in position.

For example, referring to FIGS. 5 and 6, close-up views of the firstlink 106A are provided. Specifically, FIG. 5 provides a first side viewof the first link 106A and FIG. 6 provides a second side view of thefirst link 106A. Notably, the first side view of FIG. 5 is the same viewdepicted in FIGS. 3 and 4.

As shown, the first link 106A generally includes a wall 156 extendingbetween the first end 150 and the second end 152, with the wall 156forming a segment 158 of a first line guide 160 (FIG. 5; depicted inphantom) and a segment 162 of a second line guide 164 (FIG. 6; alsodepicted in phantom). The first line 118A of the line assembly 104extends through the first line guide 160 and the second line 118B of theline assembly 104 extends through the second line guide 164. The firstline guide 160 and the second line guide 164 are arranged along thefirst pivot reference line 148A at the first end 150 of the first link106A, and similarly, the first line guide 160 and the second line guide164 are arranged along the second pivot reference line 148B at thesecond end 152 of the first link 106A.

Referring still to FIGS. 5 and 6, it will be appreciated that thesegment 158 of the first line guide 160 through the first link 106Aextends in a serpentine path between the first end 150 of the first link106A and second end 152 of the first link 106A relative to a geometry ofthe first link 106A. Notably, as used herein, the term “serpentine path”relative to a geometry of a particular link refers to a path having ashape different than a shape of the link (as may be determined by, e.g.,a centerline of the link).

Additionally, the segment 162 of the second line guide 164 through thefirst link 106A extends in a serpentine path between the first end 150of the first link 106A and the second end 152 of the first link 106Arelative to the geometry of the first link 106A. Further, for theembodiment shown, the shape of the segment 158 of the first line guide160 through the first link 106A is different than the shape of thesegment 162 of the second line guide 164 through first link 106A.

Further still, it will be appreciated from FIGS. 3 through 6collectively, that the second end 152 of the first link 106A defines afirst mating geometry and the first end 154 of the second link 106Bdefines a second mating geometry (see, e.g., FIG. 3). The second matinggeometry is complementary in shape to the first mating geometry to fullyconstrain the first link 106A relative to the second link 106B when theplurality of sequentially arranged links 106 are moved to the tensionedposition. In such a manner, the plurality of lines 118 of the lineassembly 104 are not required to align each adjacent link 106 relativeto one another, and instead are simply utilized for providing anecessary tension between adjacent links 106. Such may prevent orminimize kinks, knots, twists, etc. within the lines 118 of the lineassembly 104 during operation.

For the embodiment depicted, the first mating geometry at the second end152 of the first link 106A includes a pair of concave curves 166alternating with a pair of convex curves 168, and the second matinggeometry at the first end 154 of the second link 106B similarly includesa pair of convex curves 170 alternating with a pair of concave curves172. Notably, for the embodiment shown, a height of a first of theconcave curves 168 of the first mating geometry is equal to a height ofa first of the convex curves 170 of the second mating geometry; a heightof a second concave curve 166 of the first mating geometry is equal to aheight of a second convex curve 170 of the second mating geometry; aheight of a first convex 168 curve of the first mating geometry is equalto a height of a first concave curve 172 of the second mating geometry;and a height of a second convex curve 168 of the first mating geometryis equal to a height of a second concave curve 172 of the second matinggeometry.

However, in other embodiments, the extension tool 100 may include links106 having any other suitable geometry for mating and constrainingadjacent links 106 in a tensioned position.

As was noted above, the plurality of sequentially arranged links 106together form a first fluid flow passage 124 and a second fluid flowpassage 126 that are separate from one another when the plurality ofsequentially arranged links 106 are in a tensioned position.

Referring now to FIGS. 7 and 8, such a configuration is described ingreater detail. FIG. 7 depicts a close-up view of a junction betweenadjacent links 106 of the plurality of links 106 of the extension tool100 depicted above in FIGS. 3 and 4, and FIG. 8 provides a close-up viewof one end of one of the links 106 of FIG. 7.

As shown, a first link 106A in the plurality of sequentially arrangedlinks 106 includes a wall 156. More specifically, for the embodimentshown, the first link 106A in the plurality of sequentially arrangedlinks 106 includes a first wall 156A and a second wall 156B. The firstwall 156A of the first link 106A defines in part a first fluid flowpassage 124 and the second wall 156B of the first link 106A defines inpart a second fluid flow passage 126. For the embodiment shown, thefirst wall 156A is an inner wall and the second wall 156B is an outerwall. The outer wall substantially completely surrounds the inner wall156, such that the second fluid flow passage 126 is a generally annularpassage surrounding the first fluid flow passage 124.

For the embodiment depicted, the second wall 156B is coupled to thefirst wall 156A through one or more point contacts 174 (see FIG. 8),such that the first and second wall 156A, 156B are not continuouslyconnected along a length of each respective link 106. Specifically, forthe embodiment shown, the one or more point contacts 174 are located atthe ends of the links 106 (e.g., as first and second ends of each link106). It will be appreciated that as used herein, the term “pointcontact” with reference to the connection between the first and secondwall 156A, 156B of a respective link 106 refers to a connection thatdoes not extend significantly along a length of the respective link,such as less than about 25% along a length of a respective link 106. Forexample, in certain exemplary embodiments, the point contacts 174 mayextend less than about 15% along a length of a respective link 106, suchas less than about 10% along a length of a respective link 106, such asless than about 5% along a length of a respective link 106. Thisembodiment represents an innovative solution to limit thermal conductionpath from outer wall 156B to inner wall 156A by providing a narrowconnection element (i.e., point contacts 174).

However, in other embodiments, the first wall 156A may be coupled to thesecond wall 156B in any suitable manner.

Further, as noted above, the plurality of sequentially arranged links106 include a plurality of line guides for the plurality of lines 118 ofthe line assembly 104. In particular, for the embodiment shown, the lineassembly 104 includes a first line 118A and a second line 118B, and theplurality of sequentially arranged links 106 similarly includes a firstline guide 160 and a second line guide 164. Each link 106 includes asegment 158 of the first line guide 160 and segment 162 of the secondline guide 164. For the embodiment shown, the line guides 160, 164 arepositioned on an interior of the second wall 156B of each link 106 ofthe plurality of links 106.

It will be appreciated, however, that in other embodiments, the lineguides may instead be located elsewhere, such as on an outside of thesecond wall 156B, on an outside of the first wall 156A, on an interiorof the first wall 156A, or some combination thereof.

It will further be appreciated from the discussion above that for theembodiments depicted and described, adjacent links 106 are sealedtogether by including mating geometries at their respective ends thatare complementary in shape with the mating geometries of the adjacentlinks. The walls 156 of the links 106 are pressed together and thecontact pressure applied by the lines 118 form a contact sealtherebetween to provide a seal between such links 106.

However, in certain embodiments, it may be desirable to provide a sealbetween adjacent links to provide a more air-tight, liquid-tight sealbetween adjacent links 106 (and therefore a more air-tight orliquid-tight fluid flow passage). For example, referring to FIGS. 9 to11, three exemplary seal assemblies between a wall 156 of a first link106A and a wall 156 of a second link 106B are provided.

For the embodiment of FIG. 9, the seal assembly includes a gasket 176.The gasket 176 may be formed of any suitable material for theanticipated operations. For example, the gasket may be formed of anelastomeric material, a relatively flexible metal material, etc. Thegasket 176 may be fixedly coupled to one of the wall 156 of the firstlink 106A or the wall 156 of the second link 106B.

For the embodiment of FIG. 10, the seal includes a spline 178. For thisembodiment, the wall 156 of the first link 106A includes a groove 180,with the spline positioned therein. Similarly, the wall 156 of thesecond link 106B includes a groove 182. When the first link 106 a andthe second link 106B are moved to the tensioned position, the spline 178is further positioned within the groove 182 of the second link 106B.

For the embodiment of FIG. 11, the seal includes a complementary matinggeometry across a thickness of the wall 156 of the first link 106A andthe wall 156 of the second link 106B. For example, for the embodimentshown, the 156 of the first link 106A includes a raised knob 184, andthe wall 156 of the second link 106B includes a complementary groove186.

It will be appreciated, however, that in other embodiments, any othersuitable configuration may be provided for forming a seal betweenadjacent links 106.

Further, referring now to FIG. 12, a close-up, schematic view of a link106 of a plurality of links 106 of an extension tool 100 is provided ata distal end 122 of the plurality of links 106 in accordance with anexemplary embodiment of the present disclosure. The link 106 depictedmay be configured in accordance with one or more of the exemplaryembodiments described above, or alternatively may be configured inaccordance with any other suitable embodiment.

For the embodiment shown, the extension tool 100 includes a plurality oflines 118 extending along a length thereof, and more specificallyincludes a first line 118A and a second line 118B. Notably, however, forthe embodiment shown, the first and second lines 118A, 118B are integralwith one another at the distal end 122, such that the first line 118Ameets the second line 118B at the distal end 122. In such a manner, thefirst and second lines 118A, 118B may in fact be a single line looped atthe distal end 122. For this embodiment the lines 118 includes atransition portion 188 at the distal end 122 where the first line 118Aloops around and transition into the second line 118B.

With such a configuration, in order to ensure both the first and secondlines 118A, 118B do not completely pull out of the plurality of links106 in the event of a failure of one of the first or second lines 118A,118B, the extension tool 100 includes an attachment feature 190 coupledto the first line 118A, the second line 118, or both. More specifically,for the embodiment shown, the extension tool 100 includes the attachmentfeature 190 coupled to the transition portion 188 of the first andsecond lines 118A, 118B.

For the embodiment depicted, the attachment feature 190 defines agreater width 189 than the first and second lines 118A, 118B and isfixedly coupled to the transition portion 188 of the line 118. Forexample, the attachment feature 190 may be a crimp member, crimped ontothe transition portion 188 of the lines 118. Alternatively, theattachment feature 190 may include a base with a screw or bolt extendingto the line(s) 118 to fix the attachment feature 190 to the line(s) 118,a base welded, glued, epoxied, etc. to the line(s) 118, etc. In otherembodiments, other configurations may be provided as well. Further,although a single attachment feature 190 is depicted, in otherembodiments, multiple attachment features 190 may be provided.

More specifically, for the embodiment shown, the link 106 at the distalend includes support surfaces 198 to support the transition portion 188of the line 118, such that a load on the attachment feature 190 may beminimized. In such a manner, the attachment feature 190 may effectivelyfloat between the support surfaces 198. However, in the event of afailure of one of the first or second lines 118A, 118B, the attachmentfeature 190 may be configured to abut against a respective line guide160, 164 to prevent the line 118 remaining intact from slidingtherethrough, allowing for the line 118 remaining intact to be used toremove the plurality of links 106 from the environment.

Referring now to FIG. 13, another close-up, schematic view of a link 106of a plurality of links 106 of an extension tool 100 is provided at adistal end 122 of the plurality of links 106 in accordance with anexemplary embodiment of the present disclosure. The link 106 depicted inFIG. 13 may be configured in a similar manner to the exemplary link 106described above with respect to FIG. 12.

For example, the exemplary extension tool 100 depicted includes a firstline 118A and a second line 118 formed integrally at a transitionportion 188 at the distal end 122. The extension tool 100 furtherincludes an attachment member 190. For the embodiment depicted, theattachment member 190 is attached to the first line 118A at the distalend 122. Notably, the link 106 at the distal end 122 defines an opening192, with the first line 118A extending across the opening 192 and theattachment member 190 located within the opening 192. The openingdefines a first shoulder 194 where the first line 118A enters across theopening 192 and a second shoulder 196 where the first line 118A exitsacross the opening 192. The attachment member 190 is positioned betweenthe first and second shoulders 194, 196, without touching the first andsecond shoulders 194, 196 during normal operation.

In such a manner, the attachment member 190 is not under any significantload during normal operations (e.g., less than twenty-five percent ofthe total load on the first line 118A). However, in the event of afailure of the first line 118A or the second line 118B, the attachmentmember 190 may abut against a first shoulder 194 or a second shoulder196 to prevent the line 118 remaining intact from sliding through therespective line guides 160, 164, allowing for the line 118 remainingintact to be used to remove the plurality of links 106 from theenvironment.

Further, referring now to FIG. 14, one exemplary application of thevarious extension tools 100 of the present disclosure will be described.Specifically, FIG. 14 depicts an extension tool 100 in accordance withan exemplary embodiment of the present disclosure being utilized tonavigate through a nonlinear path within an environment, which for theembodiment shown is a gas turbine engine 200.

Specifically, for the embodiment of FIG. 14, the gas turbine engine 200is configured as a turbofan engine. The turbofan engine generallyincludes a fan section 204 and a turbomachine 206.

The turbomachine 206 generally includes a compressor section having alow pressure (“LP”) compressor 208 and a high pressure (“HP”) compressor210; a combustion section 212; a turbine section including an HP turbine214 and an LP turbine 216; and an exhaust section (not shown). Thecompressor section, combustion section 212, turbine section, and exhaustsection are each arranged in serial flow order. The LP compressor 208and LP turbine 216 are coupled through an LP shaft 218, and similarly,the HP compressor 210 and HP turbine 214 are coupled to an HP shaft 220.Additionally, the turbomachine 26 includes a casing 221 enclosing atleast in part the above-noted components of the turbomachine 206.Further, for the embodiment shown the fan section 204 includes a fanhaving a plurality of fan blades 222, with the fan and plurality of fanblades 222 being driven by the LP shaft 218.

In the callout Circle A, a close-up, schematic view of the combustionsection 212 of the exemplary gas turbine engine 200 is provided. Thecombustion section 212 generally includes an inner liner 224 and anouter liner 226, together defining at least in part a combustion chamber228. The combustion section 212 further includes a fuel nozzle 230configured to provide, e.g., a mixture of fuel and compressed air to becombusted within the combustion chamber 228 during operation of the gasturbine engine 200. An igniter (not shown) may be positioned within anigniter hole 232 of the outer liner 226 for igniting the fuel andcompressed air mixture.

After operating for an amount of time, an undesirable amount of cokebuildup may form on or within the fuel nozzle 230. For example, during ashutdown of the gas turbine engine 200, fuel may remain within the fuelnozzle 230 and residual heat within the gas turbine engine 200 may causethe remaining fuel to coke. During, e.g., a maintenance interval, theextension tool 100 may be utilized to remove the buildup of coke on orwithin the fuel nozzle 230.

The exemplary extension tool 100 depicted may be configured inaccordance with one or more of the exemplary embodiments described abovewith reference to FIGS. 1 through 13. For example, the exemplaryextension tool may generally include a plurality of links 106 movable toa tensioned position (shown) having a nonlinear, two-dimensional orthree-dimensional shape when in the tensioned position. Notably, theability to additionally be moved to a slacked position may assist withmoving the plurality of links 106 through the gas turbine engine 200environment and through the igniter hole 232.

Further, the plurality of links 106 may together define a first fluidflow passage 124 (not shown) and a second fluid flow passage 126 (notshown). The extension tool 100 may be configured to provide a first gasflow 136 through the first fluid flow passage 124 and a second gas flow138 through the second fluid flow passage 126. In order to remove thebuildup of coke on or within the fuel nozzle 230, the first gas flow 136may be a heated and pressurized gas flow defining a first operationaltemperature, and the second gas flow 138 may also be a heated andpressurized gas flow defining a second operational temperature. Thefirst operational temperature may be sufficient to burn off the cokewithin the fuel nozzle 230. The second operational temperature may beless than the first operational temperature for heating to a lesserdegree the area surrounding the coke buildup being burnt off to lessen atemperature gradient across the component.

Of course, in other embodiments, the extension tool 100 may be utilizedfor a myriad of different operations and functions.

Referring now to FIG. 15, a method 300 is provided for operating anextension tool within an environment. The method may utilize one or moreof the exemplary extension tools described above with reference to FIGS.1 through 13. Accordingly, for example, the extension tool may generallyinclude a plurality of sequentially arranged links together defining afirst fluid flow passage and a second fluid flow passage. However, inother embodiments, any other suitable extension tool may be utilized.

The method 300 generally includes at (302) providing a first fluid flowthrough a first fluid flow passage, and at (304) providing a secondfluid flow through a second fluid flow passage. The second fluid flowpassage is separate from the first fluid flow passage when the pluralityof sequentially arranged links are joined together.

For example, in certain exemplary embodiments, the extension tool may beconfigured similar to the embodiments described above, such that theplurality of sequentially arranged links are movable between a slackedposition and a tensioned position. With such an exemplary embodiment,the second fluid flow passage is separate from the first fluid flowpassage when the plurality of sequentially arranged links are joinedtogether by being moved to the tensioned position. Additionally, oralternatively, in certain exemplary embodiments, the second fluid flowpassage may be substantially fluidly isolated from the first fluid flowpassage when the plurality of sequentially arranged links are joinedtogether by being moved to the tensioned position.

Referring still to FIG. 15, for the exemplary method 300 depicted, thefirst fluid flow is a first heated fluid flow and the second fluid flowis a second heated fluid flow. With such an exemplary embodiment,providing the first fluid flow through the first fluid flow passage at(302) includes at (306) providing the first heated fluid flow throughthe first fluid flow passage at a first starting temperature (i.e., atemperature of the fluid flow as it enters the first fluid flowpassage), and providing the second fluid flow through the second fluidflow passage at (304) includes at (308) providing the second heatedfluid flow through the second fluid flow passage at a second startingtemperature. The first starting temperature may be greater than thesecond starting temperature, such as at least about 10% greater, such asat least about 25% greater, such as at least about 50% greater, such asat least about 75% greater, such as at least about 100% greater, such asup to 5000% greater, such as up to 1000% greater, such as up to 500%greater, such as up to 200% greater.

Further, with the exemplary aspect of the method 300 depicted in FIG.15, providing the first fluid flow through the first fluid flow passageat (302) includes at (310) providing a first pressurized fluid flowthrough the first fluid flow passage in a first direction. The firstdirection may generally be from a base of the plurality of sequentiallyarranged links towards a distal end of the plurality of sequentiallyarranged links. Further, providing the second fluid flow through thesecond fluid flow passage at (304) includes at (312) providing a secondpressurized fluid flow through the second fluid flow passage in the samedirection as the first pressurized fluid flow (i.e., the firstdirection).

It will be appreciated, however, that in other exemplary aspects,providing the second fluid flow through the second fluid flow passage at(304) may alternatively include, as is depicted in phantom at (314)providing the second fluid flow through the second fluid flow passage inan opposite direction than the first pressurized fluid flow (e.g., asecond direction, such as a direction extending generally from a distalend of the plurality of sequentially arranged links towards a base ofthe plurality of sequentially arranged links). With such an exemplaryaspect, the extension tool may effectively utilize the second fluid flowpassage as a vacuum.

Referring still to the exemplary aspect of the method 300 depicted, forthe exemplary aspect depicted, the method 300 is configured to reduceundue stress on a plurality of lines operable with the plurality oflinks. For example, the plurality of lines may generally extend througha plurality of line guides positioned within, or thermally coupled tothe second fluid flow passage. With such an exemplary aspect, providingthe second fluid flow through the second fluid flow passage at (34) mayfurther include at (316) providing the second heated flow at a secondstarting temperature such that the plurality of lines of the lineassembly thermally expand substantially the same amount as the pluralityof sequentially arranged links. For example, the plurality of lines maybe formed of a metal, such as tungsten or a tungsten alloy, having adifferent coefficient of thermal expansion than a material forming theplurality of links. The heated fluid flow through the first fluid flowpassage may define a starting temperature necessary for performing thedesired operations (e.g., burning off coke from a fuel nozzle). Theheated fluid flow through the second fluid flow passage may define adifferent starting temperature designed to thermally expand theplurality of lines substantially the same amount as expected thermalexpansion of the plurality of sequentially arranged links due to thestarting temperature the first fluid flow through the first fluid flowpassage.

Although not depicted, additional selectively flexible tools may beutilized in additional exemplary aspects of the present disclosure.

Further aspects of the invention are provided by the subject matter ofthe following clauses:

An extension tool including a plurality of sequentially arranged linksmoveable to a first position, the plurality of sequentially arrangedlinks rigidly fixed to one another in the first position, the pluralityof sequentially arranged links defining a first passage and a secondpassage, the second passage being separate from the first passage whenthe plurality of sequentially arranged links are rigidly fixed to oneanother.

The extension tool of any preceding clause, further including a lineassembly, wherein the line assembly is operable with the plurality ofsequentially arranged links to move the plurality of sequentiallyarranged links between a slacked position and a tensioned position,wherein the plurality of sequentially arranged links are rigidly fixedto one another when in the tensioned position.

The extension tool of any preceding clause, wherein the second passageis substantially fluidly isolated from the first passage when theplurality of sequentially arranged links are rigidly fixed to oneanother.

The extension tool of any preceding clause, wherein the first passage isan inner passage, wherein the second passage is an outer passage,wherein the inner passage is positioned inward of the outer passage.

The extension tool of any preceding clause, wherein the first passage isa first fluid flow passage, wherein the second passage is a second fluidflow passage, and wherein the extension tool further includes: a firstfluid flow device fluidly coupled to the first fluid flow passage, thesecond fluid flow passage, or both.

The extension tool of any preceding clause, wherein the first fluid flowdevice is fluidly coupled to the first fluid flow passage, and whereinthe selectively flexible extension tool further includes: a second fluidflow device fluidly coupled to the second fluid flow passage.

The extension tool of any preceding clause, wherein the first fluid flowdevice comprises a first pressurized fluid source for providing a firstpressurized fluid flow through the first fluid flow passage.

The extension tool of any preceding clause, wherein the second fluidflow device comprises a second pressurized fluid source for providing asecond pressurized fluid flow through the second fluid flow passage.

The extension tool of any preceding clause, wherein the second fluidflow device comprises a fluid pump for urging a second pressurized fluidflow from the second fluid flow passage in a direction opposite of thefirst fluid flow.

The extension tool of any preceding clause, wherein a first link of theplurality of sequentially arranged links includes a first wall and asecond wall, wherein the first wall of the first link defines in partthe first passage, wherein the second wall of the first link defines inpart the second passage, and wherein the second wall is coupled to thefirst wall through one or more point contacts.

The extension tool of any preceding clause, wherein the first wall is aninner wall, wherein the second wall is an outer wall, and wherein theouter wall completely surrounds the inner wall.

The extension tool of any preceding clause, further including: a lineassembly, wherein the line assembly operable with the plurality ofsequentially arranged links to move the plurality of sequentiallyarranged links between a slacked position and a tensioned position,wherein the second wall comprises a plurality of line guides, whereinthe line assembly comprises a plurality of lines, and wherein each lineof the plurality of lines of the line assembly extends through arespective line guide of the plurality of line guides.

The extension tool of any preceding clause, wherein the plurality ofline guides of the second wall are positioned on an interior of thesecond wall.

The extension tool of any preceding clause, further including: a lineassembly, wherein the line assembly is operable with the plurality ofsequentially arranged links to move the plurality of sequentiallyarranged links between a slacked position and a tensioned position, theline assembly comprising a first line extending along a length of theplurality of sequentially arranged links to a distal end of theplurality of sequentially arranged links; a second line also extendingalong a length of the plurality of sequentially arranged links to thedistal end of the plurality of sequentially arranged links, the firstline being integral with the second line at the distal end; and anattachment feature attached the first line, the second line, or both.

The extension tool of any preceding clause, wherein the plurality ofsequentially arranged links includes a distal link at the distal end,wherein the distal link defines an opening, and wherein the attachmentfeature is positioned within the opening.

A method for operating a selectively flexible extension tool comprisinga plurality of sequentially arranged links defining a first fluid flowpassage and a second fluid flow passage, the method including: providinga first fluid flow through the first fluid flow passage; and providing asecond fluid flow through the second fluid flow passage, the secondfluid flow passage being separate from the first fluid flow passage whenthe plurality of sequentially arranged links are joined together.

The method of any preceding clause, wherein the second fluid flowpassage is separate from the first fluid flow passage when the pluralityof sequentially arranged links are joined together by being moved to atensioned position.

The method of any preceding clause, wherein the second fluid flowpassage is substantially fluidly isolated from the first fluid flowpassage when the plurality of sequentially arranged links are joinedtogether by being moved to a tensioned position.

The method of any preceding clause, wherein providing the first fluidflow through the first fluid flow passage comprises providing a firstheated fluid flow through the first fluid flow passage at a firststarting temperature, wherein providing the second fluid flow throughthe second fluid flow passage comprises providing a second heated fluidflow through the second fluid flow passage a second startingtemperature, and wherein the first starting temperature is greater thanthe second starting temperature.

The method of any preceding clause, wherein the selectively flexibleextension tool further comprises a line assembly and a plurality ofsequentially arranged links, wherein the line assembly is operable withthe plurality of sequentially arranged links to move the plurality ofsequentially arranged links between a slacked position and a tensionedposition, wherein the second fluid flow is a second heated flow, andwherein providing the second fluid flow through the second fluid passagecomprises providing the second heated flow at a second startingtemperature such that a plurality of lines of the line assemblythermally expand substantially the same amount as the plurality ofsequentially arranged links.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. An extension tool comprising: a plurality ofsequentially arranged links moveable to a first position, the pluralityof sequentially arranged links rigidly fixed to one another in the firstposition, the plurality of sequentially arranged links defining a firstpassage and a second passage, the second passage being separate from thefirst passage when the plurality of sequentially arranged links arerigidly fixed to one another.
 2. The extension tool of claim 1, furthercomprising: a line assembly, wherein the line assembly is operable withthe plurality of sequentially arranged links to move the plurality ofsequentially arranged links between a slacked position and a tensionedposition, wherein the plurality of sequentially arranged links arerigidly fixed to one another when in the tensioned position.
 3. Theextension tool of claim 1, wherein the second passage is substantiallyfluidly isolated from the first passage when the plurality ofsequentially arranged links are rigidly fixed to one another.
 4. Theextension tool of claim 1, wherein the first passage is an innerpassage, wherein the second passage is an outer passage, wherein theinner passage is positioned inward of the outer passage.
 5. Theextension tool of claim 1, wherein the first passage is a first fluidflow passage, wherein the second passage is a second fluid flow passage,and wherein the extension tool further comprises: a first fluid flowdevice fluidly coupled to the first fluid flow passage, the second fluidflow passage, or both.
 6. The extension tool of claim 5, wherein thefirst fluid flow device is fluidly coupled to the first fluid flowpassage, and wherein the selectively flexible extension tool furthercomprises: a second fluid flow device fluidly coupled to the secondfluid flow passage.
 7. The extension tool of claim 6, wherein the firstfluid flow device comprises a first pressurized fluid source forproviding a first pressurized fluid flow through the first fluid flowpassage.
 8. The extension tool of claim 7, wherein the second fluid flowdevice comprises a second pressurized fluid source for providing asecond pressurized fluid flow through the second fluid flow passage. 9.The extension tool of claim 8, wherein the second fluid flow devicecomprises a fluid pump for urging a second pressurized fluid flow fromthe second fluid flow passage in a direction opposite of the first fluidflow.
 10. The extension tool of claim 1, wherein a first link of theplurality of sequentially arranged links includes a first wall and asecond wall, wherein the first wall of the first link defines in partthe first passage, wherein the second wall of the first link defines inpart the second passage, and wherein the second wall is coupled to thefirst wall through one or more point contacts.
 11. The extension tool ofclaim 10, wherein the first wall is an inner wall, wherein the secondwall is an outer wall, and wherein the outer wall completely surroundsthe inner wall.
 12. The extension tool of claim 10, further comprising:a line assembly, wherein the line assembly operable with the pluralityof sequentially arranged links to move the plurality of sequentiallyarranged links between a slacked position and a tensioned position,wherein the second wall comprises a plurality of line guides, whereinthe line assembly comprises a plurality of lines, and wherein each lineof the plurality of lines of the line assembly extends through arespective line guide of the plurality of line guides.
 13. The extensiontool of claim 12, wherein the plurality of line guides of the secondwall are positioned on an interior of the second wall.
 14. The extensiontool of claim 1, further comprising: a line assembly, wherein the lineassembly is operable with the plurality of sequentially arranged linksto move the plurality of sequentially arranged links between a slackedposition and a tensioned position, the line assembly comprising a firstline extending along a length of the plurality of sequentially arrangedlinks to a distal end of the plurality of sequentially arranged links; asecond line also extending along a length of the plurality ofsequentially arranged links to the distal end of the plurality ofsequentially arranged links, the first line being integral with thesecond line at the distal end; and an attachment feature attached thefirst line, the second line, or both.
 15. The extension tool of claim 1,wherein the first wall is an inner wall, wherein the second wall is anouter wall, and wherein the inner wall is connected to the outer wallthrough one or more point contacts.
 16. A method for operating aselectively flexible extension tool comprising a plurality ofsequentially arranged links defining a first fluid flow passage and asecond fluid flow passage, the method comprising: providing a firstfluid flow through the first fluid flow passage; and providing a secondfluid flow through the second fluid flow passage, the second fluid flowpassage being separate from the first fluid flow passage when theplurality of sequentially arranged links are joined together.
 17. Themethod of claim 16, wherein the second fluid flow passage is separatefrom the first fluid flow passage when the plurality of sequentiallyarranged links are joined together by being moved to a tensionedposition.
 18. The method of claim 16, wherein the second fluid flowpassage is substantially fluidly isolated from the first fluid flowpassage when the plurality of sequentially arranged links are joinedtogether by being moved to a tensioned position.
 19. The method of claim16, wherein providing the first fluid flow through the first fluid flowpassage comprises providing a first heated fluid flow through the firstfluid flow passage at a first starting temperature, wherein providingthe second fluid flow through the second fluid flow passage comprisesproviding a second heated fluid flow through the second fluid flowpassage a second starting temperature, and wherein the first startingtemperature is greater than the second starting temperature.
 20. Themethod of claim 16, wherein the selectively flexible extension toolfurther comprises a line assembly and a plurality of sequentiallyarranged links, wherein the line assembly is operable with the pluralityof sequentially arranged links to move the plurality of sequentiallyarranged links between a slacked position and a tensioned position,wherein the second fluid flow is a second heated flow, and whereinproviding the second fluid flow through the second fluid passagecomprises providing the second heated flow at a second startingtemperature such that a plurality of lines of the line assemblythermally expand substantially the same amount as the plurality ofsequentially arranged links.